Issue #1843744: Convert views/templates/views-view.tpl.php to twig.
Issue #1843746: Convert views/templates/views-view-field.tpl.php to Twig.
Issue #1843748: Convert views/templates/views-view-fields.tpl.php to twig.
Issue #1843758: Convert views/templates/views-view-row-rss.tpl.php to twig.
Issue #1843760: Convert views/templates/views-view-rss.tpl.php to twig.
Issue #1843762: Convert views/templates/views-view-summary.tpl.php to twig.
Issue #1843764: Convert views/templates/views-view-summary-unformatted.tpl.php to twig.
Issue #1843772: Convert views/views_ui/templates/views-ui-display-tab-bucket.tpl.php to Twig.
Issue #1843774: Convert views/views_ui/templates/views-ui-display-tab-setting.tpl.php to Twig.
Issue #1885564: Convert theme.maintenance.inc to Twig.
Issue #1896060: Convert aggregator module to Twig.
Issue #1898034: Convert block module to Twig.
Issue #1898038: Convert custom_block module to Twig.
Issue #1898050: Convert book module to Twig.
Issue #1898052: Convert color module to Twig.
Issue #1898054: Convert comment module to Twig.
Issue #1898062: Convert field module to Twig.
Issue #1898070: Convert file module to Twig.
Issue #1898416: Convert filter module to Twig.
Issue #1898418: Convert forum module to Twig.